The present invention relates generally to millimeter-wave components for communication applications, and more particularly to a millimeter-wave low phase noise signal source.
The present invention generally relates to high-frequency circuit devices and modules, and more particularly to millimeter-wave and microwave devices and modules. State-of-the-art integrated circuit fabrication technology which permits low cost and low noise fabrication of such devices and modules is commonly referred to as MMIC technology, or simply MMIC integrated circuits, or MMIC multi-chip modules, and generally refers to both monolithic and hybrid manufacture processing techniques. Commonly such MMIC technology employs the use of GaAs or InP semiconductor fabrication techniques. Such MMIC circuits may also be fabricated by way of standard GaAs PHEMT-based MMIC processes commonly used for mm-wave MMICs, all of which are well known in the art.
MMIC high frequency devices useful in the telecommunication and radar arts include among others, basic oscillators, voltage-controlled oscillators, mixers and converters, as well as injection locked signal sources having power greater than the injected signal. Each of the aforementioned high frequency devices is well known in the art and are embodied in a wide array of circuit configurations employing a wide variety of circuit components including field effect transistors, varactors, diodes, and the like.
More specifically, a millimeter-wave signal source is commonly employed in a variety of signal applications such as vehicular radar, mm-wave terrestrial communications, and space communications including inter-satellite communication links. Many such applications generally require an ultra-stable mm-wave local oscillator signal source employed as a component of a transmitter and/or receiver circuit. Applications as these require a constant frequency signal source having very low phase noise at frequencies in the order of 110 GHz.
There is therefore a need for a high frequency ultra-stable frequency source that is low cost and simple to manufacture.
An object of the present invention is to provide a high frequency ultra-stable signal source that is low cost and simple to manufacture.
Another object of the present invention is to provide a high frequency signal source having low phase noise in a self-contained module.
In accordance with the present invention, a high frequency signal source employs a first signal source circuit means for providing a reference output signal at frequency fr, a frequency doubling circuit means responsive to the reference output signal for providing a first output signal at frequency f2, where f2 is twice the value fr. In turn, the output of the frequency doubling circuit is coupled to a high frequency waveguide employing an antipodal finline transmission line.